body {
    color: red;
}

.user_list {
    clear: both;
    width: 50%;
    height: auto;
    overflow: hidden;
    border: 1px solid gray;
    margin: 20px;
}
.user_list li {
    clear: both;
    width: 100%;
    height: 30px;
    line-height: 30px;
    overflow: hidden;
    border-bottom: 1px dashed gray;
}